Quality and reproducibility of French publications on total hip arthroplasty.

INTRODUCTION: The goal of the Quality of Literature in Arthroplasty (QoLA) project launched in 2009 was to compare the implant results from clinical studies published in indexed scientific journals with those found in reference national registers. The potential biases in the chosen articles (country of origin, inventor involved in study, methodological quality) were systematically analyzed and the revisions per 100 observed component years (Revp100OCY) index was calculated. For a given implant, a differential factor greater than 3 between the Revp100OCY index for published series and the one from registers was considered as indicative of a potential selection (inventor) or publication (conflict of interest) bias. Although initially performed on English publications, this methodology was subsequently applied to French publications in the field of total hip arthroplasty (THA). MATERIAL AND METHODS: French publications indexed in Medline (Rev Chir Orthop and Orthop Trauma Surg Res since 2009) were analyzed. These studies involved implants designed in France (ABG, Corail stem, Cerafit/Osteal, Bousquet) or that were used worldwide (Omnifit stem, Alloclassic and Charnley-type or Müller-type implants). The articles or abstracts selected had to contain sufficient information (number of revisions, number of cases and/or revisions, average follow-up) to allow the Revp100OCY index to be calculated. RESULTS: Overall, the average Revp100OCY index for THA series published in French was 0.76, which is consistent with the worldwide average of 1.29. For the ABG System, the Revp100OCY index was 1.5, which was higher than register data (0.77). Cemented Charnley-type stems had a Revp100OCY index of 1.68 (register 0.64) and low friction arthroplasty type THA had a Revp100OCY index of 0.59 (register 0.33). The Revp100OCY index was slightly lower relative to register data for the Müller THA (0.22 versus 0.33), Corail stem (0.1 versus 0.24), Omnifit (0.26 versus 0.37) and Alloclassic (0.21 versus 0.49). Other implants without comparable register data had a relatively high Revp100OCY index: 1.2 for the Bousquet dual mobility cup and 1.35 for the Osteal/Cerafit hybrid system. CONCLUSIONS: The few studies published in French include only a limited number of cases, but their follow-up is long and the revision rate consistent with register data. There is no indication of any type of bias in French scientific publications relative to the reproducibility of THA results.

Revision rates after knee replacement. Cumulative results from worldwide clinical studies versus joint registers.

OBJECTIVE: To assess revision rates after knee arthroplasty by comparing the cumulative results from worldwide clinical studies and arthroplasty registers. We hypothesised that the revision rate of all clinical studies of a given implant and register data would not differ significantly. METHODS: A systematic review of clinical studies in indexed peer-reviewed journals was performed followed by internal and external validation. Parameters for measurement of revision were applied (Revision for any reason, Revisions per 100 observed component years). Register data served as control group. RESULTS: Thirty-six knee arthroplasty systems were identified to meet the inclusion criteria: 21 total knee arthroplasty (TKA) systems, 14 unicondylar knee arthroplasty (UKA) systems, one patello-femoral implant system. For 13 systems (36%), no published study was available that contained revision data. For 17 implants (47%), publications were available dealing with radiographic, surgical or technical details, but power was too weak to compare revision rates at a significant level. Six implant systems (17%) had a significant number of revisions published and were finally analysed. In general, developers report better results than independent users. Studies from developers represent an overproportional share of all observed component years. Register data report overall 10-year revision rates of TKA of 6.2% (range: 4.9-7.8%), rates for UKA are 16.5% (range: 9.7-19.6%). CONCLUSION: Revision rates of all clinical studies of a given implant do not differ significantly from register data. However, significant differences were found between the revision rates published by developers and register data. Therefore the different data need to be interpreted in the context of the source of the information.

[Revision rates in journal publications on joint prostheses with noticeably high failure rates in register data sets]. / Revisionsraten in Journalpublikationen zu Gelenkimplantaten mit auffällig hohen Versagensraten in Registerdatensätzen.

BACKGROUND AND AIM OF STUDY: The value of outcome quality data from clinical studies is an issue of controversial debate particularly in the context of adverse events. The aim of this study is to present and evaluate the data available from clinical studies for products that show inferior outcome in registers and to assess the possibility to draw valid conclusions from these data. STUDY DESIGN AND ANALYTICAL METHODS: Based on a structured literature research, a comparative analysis was made of the revision rates of 12 products showing significantly inferior average results in registers. The primary outcome parameter was the revision rate for any reason calculated using a standardized methodology and the parameter of revisions per 100 observed component years. RESULTS: For 5 out of 12 products not a single comparable study was available and relatively few data were available for the remaining products. A conventional meta-analysis revealed that only three products showed results that were comparable with those from registers. For 75% of products good results were published. There was not a single case where it would have been possible to identify or isolate the problems that had led to the underperformance observed on the basis of clinical studies alone. DISCUSSION: Clinical sample-based studies are not a suitable and reliable means to recognize potential product or handling problems and avoid risks for patients and physicians. In this respect registers can provide an essential contribution.

Revision rates after total joint replacement: cumulative results from worldwide joint register datasets.

In a systematic review, reports from national registers and clinical studies were identified and analysed with respect to revision rates after joint replacement, which were calculated as revisions per 100 observed component years. After primary hip replacement, a mean of 1.29 revisions per 100 observed component years was seen. The results after primary total knee replacement are 1.26 revisions per 100 observed component years, and 1.53 after medial unicompartmental replacement. After total ankle replacement a mean of 3.29 revisions per 100 observed component years was seen. The outcomes of total hip and knee replacement are almost identical. Revision rates of about 6% after five years and 12% after ten years are to be expected.

[The European Arthroplasty Register (EAR), development and rationale for supranational cooperation of arthroplasty registers]. / Das European Arthroplasty Register (EAR), die Entwicklung und Sinnhaftigkeit übernationaler Zusammenarbeit von Endoprothesenregistern.

In Scandinavia national arthroplasty registers are accepted instruments in the assessment of joint implants. They have contributed essentially to the rapid detection of inferior products and, by encouraging a continuous process of quality improvement through feedback, have helped to avoid revision operations. However, national registers have a limited significance with regard to other countries and rarely used implants. In recent years, a great number of registers have been founded. The European Arthroplasty Register (EAR), an EFORT project, aims at supporting these projects, enhancing cooperation within a network, realising further benefit through registers, and fostering scientific activities. The registers have been conceived according to the successful Scandinavian model. It is, however, necessary to adapt the concept to the individual national circumstances. In order to increase the value of register publications for other countries, it makes sense to achieve a minimum of stardardisation in datasets, definitions, product designations, as well as in evaluation and publication methods. Since the datasets of national registers implicitly reflect the prevailing national circumstances, they are always more valuable for use in the respective country than evaluations from aggregated, supranational and therefore larger datasets. Supranational evaluations may yield additional findings, but they cannot replace a national register. Therefore, EAR has been conceived as a network of independent national registers considering itself as a supplement and by no means as a competitor of the established national registers.

[Detection of inferior products in arthroplasty and implementation of findings: a retrospective analysis of the Boneloc incident]. / Erfassung von minderwertigen Produkten in der Endoprothetik und Umsetzung der Erkenntnisse: eine retrospektive Analyse am Beispiel des Boneloc-Knochenzements.

AIM: By a retrospective assessment of the Boneloc incident, a bone cement which had an inferior outcome in terms of survival rate, the value of published datasets for the detection of inferior outcomes was evaluated. METHOD: A structured literature review of English and German peer reviewed journals was conducted. The articles were assessed with respect to revision rate and statements about the product. In a standardised methodology, adjusted for number of cases and follow-up period, the revision rate was calculated. Main goal was to assess the agreement of published information from different datasets. RESULTS: In the first 4 years after Boneloc had been brought on the market exclusively experimental studies were published, most of which were in favour of the product. In 1995, clinical studies, migration analyses and register-based articles were published. Most of them reported about inferior results, in the same year Boneloc was taken from the market worldwide. Sample-based clinical follow-up studies were not able to contribute to the decision-making process, they were published with a delay of several years and were underpowered from a statistical point of view. All of them published critical statements--after the product had no longer been available on the market for many years. The average revision rate in sample-based studies exceeded the reference value in the Norwegian Arthroplasty Register 7.35-fold. When the inferior results with Boneloc were published, the product had already disappeared from the national markets in Scandinavian countries' operating registers. The central position of orthopaedic scientific societies in the entire outcome monitoring system in these countries seems to be a key factor for success and rapid reaction to identified problems. CONCLUSION: Arthroplasty registers and migration analyses have the highest value for the rapid and reliable detection of inferior outcomes in comparative analyses of published articles. Experimental studies did not agree with the performance of the product in a retrospective view, the data cannot be transferred from the estimation of future clinical outcome like survival rates. The involvement of scientific societies in the assessment and dissemination of the results is a key factor to realise potential benefit by an advanced quality monitoring project like arthroplasty registers.

Comparison of the information in arthroplasty registers from different countries.

This article considers some of the problems of the interpretation of information from other national arthroplasty registers when setting up a new register. In order for the most useful information to be available from registers much international co-operation is required between all those responsible for the design of registers as well as those who gather, assess and publish the data.

Key factors for a successful National Arthroplasty Register.

Since the introduction of the first National Arthroplasty Register in Sweden in 1975, many other countries have tried to adopt the successful Scandinavian system. However, not all have overcome the political and practical difficulties of establishing a working register. We have surveyed the current registries to establish the key factors required for an effective database. We have received detailed information from 15 arthroplasty registers worldwide. The legal conditions under which they operate together with the methods of collection and handling of the data differ widely, but the fulfilment of certain criteria is necessary achieve a high degree of completeness of the data to ensure the provision of statistically relevant information.

[Influence of local anesthesia and energy level on the clinical outcome of extracorporeal shock wave-treatment of chronic plantar fasciitis]. / Einfluss von Lokalanästhesie und Energieflussdichte bei niederenergetischer Extrakorporaler Stosswellentherapie der chronischen Plantaren Fasziitis -- Eine prospektiv-randomisierte klinische Studie.

BACKGROUND: The efficacy of low energy extracorporeal shock wave treatment (ESWT) for chronic plantar fasciitis is discussed controversially. It is unclear whether the simultaneous application of local anesthesia (LA) interferes with clinical outcome. METHODS: 60 patients with a chronic plantar fasciitis were enrolled in a triple-arm (20 patients per group), prospective randomized and observer-blinded pilot trial. The patients were randomly assigned to receive either active ESWT without LA (;3 x 1 500 shocks, total energy flux density [EFD] per shock 0.09 mJ/mm(2) [Group A]), ESWT with LA (3 x 1 500 shocks, EFD 0.18 mJ/mm(2) per shock [Group B]) or ESWT with LA (3 x 1 500 shocks, EFD 0.09 mJ/mm(2) [Group C]). Main outcome measures were: pain during first stepps in the morning (measured on a 0-10 point visual analogue scale) and number of patients with > 50 % reduction of pain and no further therapy needed, measured at 6 weeks after the last ESWT. RESULTS: Group A improved in the VAS from 6.4 (SD: 1.7) to 2.2 (SD: 2.6) points, group B from 6.7 (SD: 1.5) to 4.1 (SD: 2.4) points, group C from 6.2 (SD: 1.6) to 3.8 (SD: 2.5) points. A reduction of pain of at least 50 % was achieved in 60 % of group A, in 36 % of group B and in 30 % of group C. Group A without LA showed a significantly higher improvement in the VAS and subjective evaluation than groups B (p = 0.007) and C (p = 0.016). CONCLUSION: At 6 weeks success rates after low-energy ESWT with local anesthesia were significantly lower than after identical low-energy ESWT without local anesthesia. Higher energy levels could not balance the disadvantage of this effect. LA significantly influenced the clinical results after low energy ESWT in a negative way. Blinding patients by LA in ESWT studies must therefore be considered a systematic error in study design.

[Radiological appearance of the cementless ALLOCLASSIC SL-stem implanted in very old patients with primary hip osteoarthritis]. / Radiologisches Erscheinungsbild des zementfreien ALLOCLASSIC SL-Schaftes bei sehr alten Patienten mit primärer Coxarthrose.

AIM: The radiological appearance of the cementless ALLOCLASSIC SL-stem, implanted in patients with primary osteoarthritis of the hip and aged at least 80 years at time of surgery, was investigated. METHOD: 66 hips in 58 patients were analysed. 17 patients (19 hips) died in the interim, 5 patients (5 hips) were not available for follow-up because of health reasons (4) or lack of co-operation (1). 1 stem had to be explanted after a periprosthetic fracture of the femur. Finally, 41 total hip arthroplasties in 35 patients could be analysed after an average of 67.9 months (39.2-93.4). RESULTS: Bone atrophy - especially in the proximal Gruen zones - was frequently found. In contrast, radiolucent lines and osteolyses were rare occurrences. The Harris Hip score was preoperatively on average 33.0 points, at time of follow-up 81.7 points. The survival rate (endpoint aseptic loosening) was 100 % after a mean follow-up of 5.7 years. CONCLUSION: Also in very old patients the implantation of a cementless stem is possible and provides very good results.

Cementless total hip arthroplasty in patients older than 80 years of age.

We reviewed 80 patients (87 hips) who were older than 80 years of age at the time of cementless total hip arthroplasty. An Alloclassic SL stem had been implanted in all patients. A variety of cementless acetabular components was used. After a mean follow-up of 69.3 months (39.2 to 94.1) 48 hips in 43 patients were analysed clinically and radiologically. One patient had sustained a traumatic periprosthetic fracture of the femur with subsequent exchange of the stem 73 months after operation. Thirty-two patients (34 hips) had died and five patients (five hips) were unavailable for follow-up because of health reasons (four patients) or lack of co-operation (one patient). If the endpoint is defined as removal of the prosthesis because of aseptic loosening, the survival rate was 100% for the cup and stem after 78 months. The mean Harris hip score was 81.9 points. Radiolucent lines and osteolysis were seldom found.

[Minimally invasive medial unicompartmental knee replacement]. / Der minimal-invasive mediale Halbschlitten. Möglichkeiten und Grenzen.

Medial unicompartmental knee replacements have been used for more than 40 years. Due to increased experience in determining the indication for use and improvements in design of the prosthesis and tribology, the long-term results have now reached a high level. The advantages of these systems are less bone loss and better proprioception. The disadvantage is the risk of panarthrosis, which might be reduced by accurate indications for operations. Good indications are patients older than 60 years with normal weight and normal sports activity. Well-functioning collateral and cruciate ligaments are mandatory. Due to the fact that during implantation eversion of the patella is not necessary, a minimally invasive approach might be used. Overcorrection of the mechanical axis of the leg should be avoided. By observing these principles, very good long-term results can be achieved with medial unicompartmental arthroplasty. Better proprioception and better mobility of the knee are advantages of these implants compared to total knee arthroplasty. In the case of revision with a bicondylar implant, the situation is less complex compared to revisions after osteotomies or bicondylar replacements. Remobilization in this situation is shorter with better results compared to a revision with a bicondylar prosthesis.

Side-effects of extracorporeal shock wave therapy (ESWT) in the treatment of tennis elbow.

Apart from a few observational reports, there are no studies on the side-effects of extracorporeal shock wave therapy (ESWT) in the treatment of insertion tendopathies. Within the framework of a randomised, placebo-controlled, single-blind, multicentre study to test the effectiveness of ESWT in the case of lateral epicondylitis (LE), side-effects were systematically recorded. A total of 272 patients from 15 centres was allocated at random to active ESWT (3 x 2000 pulses, energy flux density ED(+) 0.04 to 0.22 mJ/mm(2) under local anaesthesia) or placebo ESWT. In all, 399 ESWT and 402 placebo treatments were analysed. More side-effects were documented in the ESWT group (OR = 4.3, CI = [2.9; 6.3]) than in the placebo group. Most frequently, transitory reddening of the skin (21.1%), pain (4.8%) and small haematomas (3.0%) were found. Migraine was registered in four and syncopes in three instances after ESWT. ESWT for LE with an energy flux density of ED(+) 0.04 to 0.22 mJ/mm(2) is a treatment method which has very few side-effects. The possibility of migraine being triggered by ESWT and the risk of a syncope should be taken into account in the future. No physical shock wave parameters could be definitely identified as the cause of the side-effects observed.

[Blood transfusion in total hip endoprosthesis operations in relation to Redon drainage and pressure bandages. An innovation in surgical method]. / Blutverbrauch bei Hüfttotalendoprothesenoperationen in Abhängigkeit von Redondrainage und Druckverband. Eine Innovation im operativen Vorgehen.

PROBLEM: There is a difference in the use of redon drainage following hip arthroplasty worldwide. The aim of the study was to find the best version. METHOD: In a prospective randomized study including 158 patients with coxarthrosis we implanted cementless Alloclassic hip-endoprostheses and registered consumption of blood, blood loss, hemoglobin level, subcutaneuos hematoma, swelling of the proximal thigh, bleeding and exsudation of the wound in four groups supplied with three, two (subcutaneously and subfascial) and one (subcutaneously or subfascial) drainage with compression bandage and one group with two redons (subcutaneously and subfascial) without compression bandage. For prophylaxis of deep vein thrombosis we used low dose heparin. RESULT: We could demonstrate, that the application of two redons one subcutaneously and one subfascial gave the best result. Compared to the conventional procedure with three redons we achieved a reduction of 47% of blood units, a significant reduction of exsudation and bleeding out of the wound, subcutaneous hematomas and a reduced swelling of the proximal leg in addition to better clinical conditions of the patients. The reason is a more accelerated stop of the bleeding out of the spongy bone. The application of one drain subcutaneously or subfascial showed no further reduction of blood loss, but an increase of wound exsudation and bleeding out the wound and an increase of subcutaneous hematomas. Sufficient external compression of the area of operation by a compression bandage is very important. Disadvantages as a result of changing the way of drainage have not been detected. CONCLUSION: The use of two Redons one subcutaneously and one subfascial showed an obvious benefit without any clinical disadvantage compared to 3 redons or no drainage.